Field of the Invention
The present invention relates to a display device preventing the luminance unevenness by voltage drop using an auxiliary electrode.
Discussion of the Related Art
Generally, an electronic appliance, such as a monitor, a TV, a laptop computer, and a digital camera, include a display device to realize an image. For example, the display device may include a liquid crystal display device and an organic light-emitting display device.
The display device may include a light-emitting structure for realizing a specific color. For example, the light-emitting structure may include a lower electrode, a light-emitting layer and an upper electrode, which are sequentially stacked.
The display device may use an auxiliary electrode in order to prevent the voltage drop and the luminance unevenness due to a resistance of the upper electrode. The auxiliary electrode may be disposed on a non-light-emitting area of the display device disposed outside an emitting area of the display device. The light-emitting structure may be disposed on the emitting area of the display device. The auxiliary electrode may be electrically connected to the upper electrode of the light-emitting structure.
In the display device, various structures may be used to connect between the upper electrode and the auxiliary electrode. For example, the display device may prevent the light-emitting layer from being deposited on a portion of the auxiliary electrode using an under-cut region formed by a lower passivation layer and an over-coat layer disposed between the auxiliary electrode and the upper electrode. Thus, in the display device, the upper electrode formed by a process having better step coverage than the light-emitting layer may be electrically connected to the portion of the auxiliary electrode in which the light-emitting layer is not deposited.
However, the upper electrode may be formed to have a relatively thin thickness, or may be partially broken in the under-cut region formed by the lower passivation layer and the over-coat layer. Thus, in the display device, the electrical connection between the auxiliary electrode and the upper electrode by the under-cut region becomes unstable, and the luminance unevenness due to the resistance variation of the upper electrode may occur.